A permanently installed hydraulic flow monitor can be used to monitor hydraulic system performance as part of the machine rather than as temporary test equipment. The Webtec® CTA Series is designed for permanent installation in industrial, on-highway and off-highway machinery. The datasheet identifies applications including closed-loop control, real-time diagnostics, safety interlocks and inclusion in predictive maintenance and IoT systems. 

Hydraulic flow data can be incorporated into machine diagnostic and predictive maintenance systems. The CTA Series is specifically designed for inclusion in real-time diagnostics and predictive maintenance or IoT systems, providing flow information to the wider monitoring system. This can allow hydraulic performance to be monitored while the equipment is operating. The CTA provides the measurement signal; how that information is analysed or used to identify maintenance requirements depends on the machine's control or monitoring system.

It depends on the information and electrical interface required by the machine. CTA models with an SAE J1939 compatible CAN-bus interface report both hydraulic flow and temperature, while the 4–20 mA versions provide an analogue flow output. The J1939 version uses a Deutsch automotive connector, while the 4–20 mA version uses an M12 connector. Both versions operate from a 9–28 V d.c. supply. 

Yes, depending on the output version selected. The J1939 versions of the CTA Series report both hydraulic flow and temperature, with the datasheet specifying temperature accuracy of ±1 °C / ±2 °F. The 4–20 mA versions report flow only, so temperature is not available from those models. If both parameters are required by the machine-control or monitoring system, the J1939 version should therefore be selected. 

Yes. The CTA flow block is capable of measuring hydraulic flow in either direction. Fluid passing through the flow block rotates an internal turbine, and the turbine frequency is used to calculate the flow. This bi-directional measurement capability can be useful where flow direction can change during normal machine operation. 

The CTA Series is available in three principal flow sizes. Metric BSPP versions cover 3–60 L/min, 5–150 L/min and 8–300 L/min, while SAE versions cover 0.8–16 US gpm, 1.3–40 US gpm and 2–80 US gpm respectively. The maximum rated pressure stated for the range is 420 bar / 6,000 psi. The required flow range, port type and output signal should be considered when selecting the model. 

The CTA Series has a specified flow accuracy of better than 1% of full scale (FS) and repeatability of better than ±0.2%. For J1939 versions, the stated temperature accuracy is ±1 °C / ±2 °F. The appropriate flow range should be selected for the application using the calibrated ranges specified for each CTA model. 

Yes. The CTA Series can be mounted in any orientation. However, mounting orientation is only one part of achieving a suitable installation. Webtec also recommends using flexible hoses of 1–2 metres / 3–6 ft and ensuring that the inlet and outlet connections have a similar bore size to the flow block. The location of bends and sources of flow pulsation should also be considered when positioning the monitor. 

The CTA should be installed where the connected pipework will not unnecessarily disturb the flow entering the meter. Webtec recommends flexible hoses 1–2 metres / 3–6 ft long and inlet and outlet connections with a similar bore to the flow block to avoid venturi or constriction effects. A sharp bend, particularly at the inlet, can result in unexpected flow readings. Where repetitive pulsation causes lateral pipe movement, the hoses should also be firmly clamped. 

Not where the pump is a source of significant flow pulsation. The CTA installation instructions recommend that the flow monitor is not positioned close to sources of pulsating flow, such as certain piston pumps. Where repetitive pulsation causes lateral movement of pipework against the ports, the connected hoses should be firmly clamped. The most appropriate location will depend on the hydraulic circuit and installation. 

Yes, where the CTA is installed on a vehicle the datasheet specifies chassis bonding for EMC purposes. The flow monitor should be bonded to the vehicle chassis either through the metal pipework or by using a bonding strap. An earth bonding point is identified on the installation drawing to assist with the installation. 

For the CTA Series, filtration must be better than DIN ISO 4406: 19/16/13 or NAS 1638: 7. The datasheet states that this cleanliness level is typically achieved using 10-micron system filtration. Maintaining the specified fluid cleanliness is therefore an important installation and operating requirement for the turbine flow monitor. 

The CTA Series is designed for permanent use on industrial, on-highway and off-highway machinery. With the cable connected, its enclosure is designed to meet IP6K9K, and the specified ambient temperature range is -40 to 85 °C / -40 to 185 °F. The datasheet also lists testing and EMC/ESD requirements including SAE J1455, ISO 11451, CISPR 25 and SAE J1113 standards. The CTA is also designed to meet IP6K9K. 

CTA flow monitors operate from a 9–28 V d.c. supply. J1939 versions use a four-pole automotive Deutsch-compatible DT15 male connector, with connections for supply, ground, CANH and CANL. The 4–20 mA version uses an M12 connector and provides a three-wire analogue output, with 4 mA representing zero flow and 20 mA full-scale flow. The J1939 interface supports CAN-bus baud rates of 250 kHz and 500 kHz. 

All CTA turbine flow meters are calibrated at a mean viscosity of 21 cSt using ISO 32 hydraulic mineral oil to ISO 11158 category HM. Other calibration requirements are available on request and should be discussed with Webtec. Calibration certificates can also be supplied on request as a chargeable option. This is more precise than assuming that one standard calibration will represent every possible fluid viscosity or application. 

The CTA Series is specified for mineral oils to ISO 11158. For other hydraulic fluids, Webtec recommends consulting the sales office rather than assuming compatibility. Depending on model, connection options include BSPP and SAE ORB ports. Standard seals are FKM, with EPDM seals available by consulting the sales office. The flow-meter body is manufactured from anodised high-tensile aluminium 2014A, with aluminium, steel and stainless-steel internal parts. 

Yes. J1939 versions of the CTA provide an SAE J1939 compatible CAN-bus interface for integration with compatible machine systems. They transmit flow and temperature data, with the datasheet giving a 50 ms transmission rate for its CTA300 communication example. CAN-bus operation is available at 250 kHz or 500 kHz. Other PGNs, addresses, flow ranges and engineering units are also available, so the required communication configuration should be confirmed when specifying the monitor. 

Yes. The CTA Series is specifically described as suitable for closed-loop control, real-time diagnostics, safety interlocks and inclusion in predictive maintenance or IoT systems, including systems intended to enable autonomous vehicle operation. The CTA provides the hydraulic flow signal and, on J1939 models, temperature data for integration into the wider machine system.